A wireless local area network subsystem corresponding to the 802.11ad protocol operates on a frequency band of 60 GHz, and is mainly used to transmit wireless high-definition audio and video signals inside a home, to provide a more complete high-definition video solution for a home multimedia application. However, in the current 802.11ad protocol, only one channel can be used once to transmit a signal. To improve a transmission throughput, a plurality of channels can be simultaneously used to transmit a signal in a next-generation 802.11ad protocol. Channel aggregation is a multichannel-based signal transmission manner. When a signal is transmitted through channel aggregation, how to further improve signal transmission reliability is a problem that needs to be resolved urgently.